Not if it's a well-designed mechanism - and it is. The Hollowtech II works on any BB-shell. Well - 68mm & 73mm. As the bearing-mechanism is attached outside the frame, one doesn't need to measure the axle-length required so it will fit inside properly. The crankset for these are 2-piece. This consists of the chainrings and crank-arm for the drive-side being attached together to a long axle. This fits through the BB-shell and it then attached to the separate left-side crank-arm. Hence: Two-Piece. The internal portion of the Hollowtech II bottom-bracket is just an empty plastic tube through which goes the axle which is attached to the chainrings and right crank-arm. Then is attached to the left side crank-arm.

Get it? I suggest you Google-up some pictures off the web.